Reps. Jason Altmire (D-Pa.) and Mark Critz (D-Pa.) fought to win over Democratic diehards while maintaining their centrist credentials in a Monday night debate, showing the tough position the two are in: running in a hotly-contested Democratic primary in a GOP-leaning district.

Critz slammed Altmire for voting to repeal Democrats' health insurance reform law, and while he's said he would also have voted against it, nevertheless came close to praising its reforms during the debate.

"The system we had was not working. Is the healthcare bill the answer? Does it solve all the issues? Well, no. It needs a lot of work," he said before adding he had "voted every time to support the bill in its current form and worked to improve it."

He also attacked Altmire for voting for the GOP-backed Balanced Budget Amendment.

Altmire hit Critz for voting to defund Planned Parenthood, although he touted his anti-abortion-rights beliefs in arguing to defend the organization. "I am pro-life, but I have voted at every opportunity to provide funding for Planned Parenthood,” he said. "My position is funding for Planned Parenthood helps prevent abortions."

During redistricting, Republicans threw the two men together into one slightly Republican district outside of Pittsburgh that is heavy with blue-collar voters. Both have sought in the primary to highlight votes in line with the district's Democratic base, although their own centrist voting records have constrained them.

Critz has the backing of most of the district's unions, an important ally in the area, while Altmire has a major geographic edge, as many more of his current constituents live in the new district.

They will face off in an April 24 primary, with the winner likely to face Republican attorney Keith Rothfus, whom Altmire narrowly defeated in 2010.